K'rrik, Son of Yawgmoth

• WOTC Official Reminder Textofficial rules
  Lifelink — Damage dealt by this creature also causes you to gain that much life.

• WWizards of the Coast2019-08-23
  Official Ruling
  K'rrik's last ability resolves before the spell that caused it to trigger. It resolves even if that spell is countered.
• WWizards of the Coast2019-08-23
  Official Ruling
  K'rrik's ability doesn't modify or reduce costs you pay. It changes only how you may pay those costs.
• WWizards of the Coast2019-08-23
  Official Ruling
  You can't pay 2 life to pay for generic mana in costs you pay, even if an effect says that you must spend black mana to pay that generic mana.
• WWizards of the Coast2019-08-23
  Official Ruling
  If a cost contains a mana symbol that may be paid in multiple ways, such as , , or , you choose how you'll pay it before you do so. If you choose to pay this way, K'rrik's ability allows you to pay life rather than pay that mana.
• WWizards of the Coast2024-06-07
  Official Ruling
  A Phyrexian mana symbol contributes 1 toward the mana value of a card, even if life is paid for it. Specifically, K'rrik's mana value is always 7.
• WWizards of the Coast2024-06-07
  Official Ruling
  K'rrik's ability lets you pay 2 life for  in any cost you pay, including the mana costs of spells, activation costs, and even costs for special actions (such as morph). Any time you pay mana, that's a cost.

Rulings via Scryfall